This project focuses on leiomyomata (fibroids) and examines factors related to their pathogenesis, diagnosis and/or potential treatment. Ongoing work seeks to evaluate the utility of the progesterone response modulator CDB2914 as a treatment of fibroids. We previously investigated the effect of single doses of the agent on the menstrual cycle in women, and showed that doses of 100 or 200 mg retard folliculogenesis and precipitate menses, in the follicular and luteal phase respectively. Two randomized double-blind placebo-controlled clinical trials from our group showed reduction in fibroid size in women receiving CDB 2914 at a daily dose of 10 or 20 mg for three months, as compared to women receiving placebo. One of these studies showed continued efficacy during a second three-month study. We also are using gene arrays to evaluate the pathophysiology of leiomyomata.